In known battery powered vegetation trimmers of this type, a battery pack powers an electric motor. A rotary output of the electric motor directly drives a line support structure in a rotatable manner. The line is supported by the line support structure so that an end section of the line extends from the structure. As the structure rotates, the end section of the line is rotated and will cut any light vegetation or grass which comes into the path of the line.
A vegetation trimmer is designed so that the weight of the trimmer is supported by the user. The height, orientation and direction of movement of the cutting head of the trimmer, when in use, is determined by the way in which the user holds and moves the trimmer. As a vegetation trimmer has to be supported by the user, it is important to keep the weight-of the trimmer to a minimum. This is achieved by minimising the weight of the various component parts of the vegetation trimmer, for example, the weight of the battery or motor.
A problem with known battery powered vegetation trimmers is achieving an acceptable run time before the battery requires recharging. In order to achieve acceptable run times large (and thus heavy) batteries or relatively expensive batteries have to be used, neither of which are ideal. Therefore, when designing a battery powered vegetation trimmer, there is always a balance between run time and either weight or expense.
One way of overcoming this problem is to use two interchangeable batteries to power a vegetation trimmer. When one of the batteries becomes discharged through use on the trimmer it is replaced by a second battery, which itself can be replaced by a third battery or by the first battery which is recharged while the second is in use. The disadvantage to this solution is that at least two batteries must be purchased by a user, which adds cost. Also, replacement of the batteries interrupts the use of the trimmer.